[Sclerosis and carcinogenesis]

Morphological analysis of the sclerotic changes in peripheral lung carcinoma (PLC) and nephrosclerosis in renal-cell carcinoma (RCC) established a promoting role of sclerosis in carcinoma development. The pneumosclerosis role as a background process in the PLC development is proved by the following facts: high proportion (83%) of the carcinoma in the scar among PLC; identity of the scar collagen composition in PLC and that in metatuberculosis and metapneumonic pneumosclerosis foci; detection of metatuberculosis foci in 75% of PLC; the presence of the precancerous changes in the epithelium entrapped in the pneumosclerotic foci, not only with signs of morphological atypia, but with the disturbance of nuclear DNA and cellular oncogene expression as well. The association of RCC with nephrosclerosis is shown by a high proportion (82.7%) of the RCC development against the background of nephrosclerosis; the dependence of the so-called cortical adenoma development on the degree of nephrosclerosis; epithelial proliferation in the nephrosclerotic foci with the appearance of undifferentiated cells with the altered DNA content and the expression of cytokeratins and vimentine. Carcinoma morphogenesis against the background of sclerosis may be described as follows: development of sclerosis (focal and/or diffuse), the appearance of the focal epithelial hyperplasia in the scar, dysplasia or adenoma and finally carcinoma.